Concrete mixer



Nov; 7, 1944.

L. G. HILKEMEIER CONCRETE MIXER wFiled. Jan. 28, 1942 2 Sheets-Sheet 1'Louis GHillremeier,

Patented Nov. 7, 1944 UNITED STATES l OFFICE I q 2,362,435 vCONCRETEMIXER Louis G. Hilkerneier, Milwaukee, .Wis., assignor to AChain Belt Company, Milwaukee, Wis., a cor- .poration of.WisconsinApplication January 28, 1942, Serial No.428,603

4 Claims.

Patent N0..2,045,532, granted June 23, 1936, on,

an application filed by 'John C.- Merwin and Charles F. Ball. Thepresent invention however, represents a further development of certainchargingmechanisms. devised by the-said Ball, .0

primarily for usein connection with the inclinedaxis type of machinedisclosed. in'the aforesaid patent,,which mechanisms are fully set forthin U. S. Patents Nos. 2,265,751 andi2,265,752,geach granted December 9,1941, and in U. S; Patent No. 2,281,820, grantedMay 5, 1942. 1

Briefly, the last mentioned patents and appli cation disclose avcharging hopper structure for the open upper end of a rotatableinclined-axis mixing drum, said structurefincluding a non-rotatablehopper and being mounted for reciprocatory movements toward and from thedrum opening upon I a shaft disposed axially of the drum and extendingthrough its said opening to and through the rear inclined wall of thehopper. While in actual practice these constructions have been foundquite eificient in the accomplishment of their intended purpose ofrapidly inducting the concrete-making solids into. the drum, at the sametime the extension of the supporting shaft to and through the rear wall,of the hopper, notwithstanding that its dimensions were nominal, impededto some extent the flow of the materials down the inclined rear wall ofthehopper toward which the materials naturally gravitate,

It is one of the principal objects of'the present invention, thereforatoprovide a charging hopper construction for a mixer of this type whereinthe supporting shaft'doesnot extendto the rear inclined wall of, thehopper, thereby providing for theunobstructed passage of the mateingmaterials-thereto through the hopper, and it is a still further object'ofthis invention to provide an improved ventinglmeans for that purpose.l y v t With the above and other objectsin view which will appear asthe, description proceeds, the invention resides in the novel details ofconstruc- Referring to the accompanying drawings form- ,ing apart ofthisspecification, in which like reference characters designate lik parts inallthe Iviewsz' Figure 1 is a longitudinal vertical sectional vation andupon a' slightly larger scale, of the non-rotating hopper and axiallymovable with;

it to and from a position inwhich its perimetric portion engaged withthe portion of. the drum surrounding the drumopening, inwhich positionthe said annulus rotated'with the drum; Itis a further object of thepresent invention to provide an improved bearing. and seal constructionfor this annular member.

The said Ball application Serial No. 354,521 further disclosed a ventingarrangement for, the. hopper, providing for-the escape of air from the.drwn during the char in at th t m k parts shown in Figure 1,takenapproximately on looking in the direction of the arrows;

' Figure 3 is an elevational view of the hopper structure per se, partlybroken away and without the intermediate annulus, as; seenfrom the leftof Figure 1; 7

the plane indicatedbylthe line 22 of Figure 1,

Figure 4' is an'elevational view of the interme- .diate-annular memberper se, as seen from the rightlnl igurekand v V I Figure'5 is anenlarged cross sectional view throughthe improved bearing and sealbetween the hopper structure and intermediate annulus.

Referring more particularly to the said drawings there is illustrated,for the purposes of the present disclosure but not by way of limitation,the rear end portion of; a mixingdru'mlfl, of a high-dischargetruck-mounted concrete mixer of the type exemplified in the aforesaidpatents,

-which drum. is mounted in a framework It for rotation about an axisinclined to the horizontal by any suitable well-known means, not shown.

The end of the drumisprovided with the material-transfer opening 12which has associated with ita charging hopper structure, similar incertain respects to that disclosed in thesaid Ball patents andapplication, which structuremay-be mounted by the drum H! forreciprocating-movements in the direction of the drum axis to and from"said material-transfer opening l2. The

movements away from the drum or toward the right from the positionsshown in'Figure 1, are

for the purpose of permitting discharge of the and gravel or crushedstone, through the opening l2 and into the drum where they will betransformed into the finished concrete mixture by the usual helicalmixing blades IIJ upon rotation of the drum. In this position the hopperstructure also prevents discharge of the materials through the opening12 during mixing.

The advantages of mounting the hopper structure upon the drum ratherthan upon the supporting framework I may be readily appreciated sincesuch mounting maintains a constant re; lationship between or alinementof the drum and hopper structure, whereas if the hopper were mountedupon the framework ll, distortion of such framework due to the twistingand weav-x ing movements of the truck chassis upon which the mixer unitis mounted, as it travels over rough ground, might misaline the drum andhopper to such an extent as to result in leakage of materials from thedischarge opening during mixing and also possibly during charging, ifthe truck happened to be upon an uneven surfaceat that time.' 7

As here shown, the hopper structure comprises a non-rotatable hopper l3of more or less inverted coniform shape, the forward portion l4 of thewall of which is provided with a discharge port 15 through which thematerials introduced through the open top of the hopper may pass intothe drum by way of the transfer opening 12 of the latter, as will bereadily understood from Figure l. The opposite or rearward portion l6 ofthe hopper wall inclines sharply downwardly, substantially as shown inFigure 1, to the said discharge ,port 15 and since the action of gravityupon materials introduced into the hopper tends to cause such materialsto seek and traverse this portion ofthe hopper wall, it is importantfrom the standpoint of rapid charging of the materials into the drumthat this portion of the wall be free from obstructions which wouldinterfere with the movement of materials along it.

In order to provide a construction in which this rear wall isunobstructed and thus facilitate the charging of the materials, thepresent inven-' or bearing 20 which is supported by the drum' 10 as, forinstance, by means of the radially extending rods or tubes 21 rigidlysecured to portions of the helical mixing blades In, or directly to theshell of the drum, and to the said sleeve,

as will be readily understood. In the construction shown the shaft 19 isrigidly attached to the bracket l8 and since the hopper structure doesnot rotate, the said shaft is journal'ed in the sleeve 23 so that thedrum may rotate around it. On the other hand the shaft is axiallyslidable within the said sleeve so that the hopper structure may bemoved away from the drum, or toward the right, as viewed in Figure l, in

order to permit discharge of the mixture, and v subsequently return tothe Figure 1 position to condition the apparatus for chargingand mixing,as is fully disclosed in said prior Ball patents.

It will be noted that the shaft I9 extends into the hopper structureonly approximately to the discharge port l5 and its end is materiallyspaced from the inclined rear portion l6 of the hopper wall whereby itoifers no interference to materials. moving downwardly along said walland into the drum. While the supporting bracket 18 blocks off a portionof the discharge port I5, such obstruction as may be'imposed thereby toflow of the materials through said port occurs in an upper segment ofthe latter rather than along the sloping rear or bottom wall l6 of thehopper to which the materials naturally gravitate; and the impediment tothe materials occasioned by the bracket is offset by the advantageresulting from the creation of a void forward of the bracket throughwhich air may pass to the air vent, as will appear more fully below.Furthermore, the said bracket may be so shaped and the use of theconstruction just described.

As above indicated the hopper I3 is non-rotatable, linkage 25 similar tothat disclosed in the said Ball patents, Nos. 2,265,751 and 2,265,752,being provided between the hopper and frame H for preventing rotationwhile at the same time permitting reciprocation; and as in the saidpatents, the hopper element carries an intermediate ring member 26journalled thereon for engagement with and rotation by the drum l0, whenthe parts are in the charging or mixing position illustrated inFigure 1. An annulus ll, of angular cross section, is rigidly carried bythe collar H and one leg thereof conveniently forms one member of ajournal bearing 36 for the ring member 26, the other or ring-carriedmember of which comprises an annulus 30, which is rigidly mounted uponthe said ring member as by the bolts 3| and spacing bushings 32. Aretaining ring 30', also secured by bolts 3|, serves to maintain theintermediate ring assembly 26, 26', 30 in operativeposition on theannulus H.

The annulus 30 is provided with an annular recess 33 (see Figure 5) inwhich any suitable packing or sealing material 34 may be positioned andheld snug against the member [1' by suitable means such as a coil spring35, whereby to provide a labyrinth seal forprotecting the hearing 36against extraneous material. A grease fitting 31 may be provided,communicating through members I! and H with the said bearing, to supplylubricant thereto.

In order to further protect this hearing against the entry ofabrasiveconstituents of the concrete mixture thereto an additional seal isprovided, comprising a resilient sealing ring 40, which is mounted uponthe member 11', as will be clear from Figures 1 and 5. This sealing ringis pro vided with a plurality of outwardly extending circumferential.ribs or flanges 4| which are axially spaced from one another to providean annular space 42 between them. These flanges are constructed toextend straight out from the base ring 40, as indicated by, broken linesof Figure 5,

but in the assembly of the parts, they are engaged of them in an outwarddirection, as by materials within the drum seeking to [work outwardly,merely forces them more firmly against the inner surface of the annulus26' and any tendency of the concrete materials to work past them is-thusresisted very efiiciently. The space 42 between the ribs 4| ispreferably filled with grease by means of a grease fitting 45 and pipe45, communicating withthe said space, and the curved tensioned conditionof the right hand flange 4| is likewise effective in resisting anytendency of such grease to work past it. Should there be any escape itwould be towards the left as viewed in Figure 5, past the left handflange4land into the drum.

In the said prior Ball application Serial No. 354,521 there wasdisclosed a means for venting the drum during charging, to prevent thebuilding up of pressures therein during the charging operation. Thepresent invention contemplates an improvement in this venting means,which as here shown, comprises a substantially rectangular shield 50having side walls and a bottom wall, which shield is pivotally mountedas at 5| by a bracket 52 carried by the portion I4 of the hopper wall.This shield extends downwardly in front of the upper portion of thesupporting bracket l8, its side and bottom walls being suitablyconformed to the contour of the parts,'and the said bracket I8 isprovided with a venting aperture 54 which affords communicationbetweenthe interior of the shield member 50 and the area forward of thesaid bracket where, as above indicated, a void is formed duringcharging. The upper end of the shield may be open as shown in Figure 1and in addition thereto a vent opening 55 may be provided in the wallportion 14 V to accommodate escape of air from the drum in the event theopen upper end of the shield should become clogged. By pivotallymounting the shield on the bracket 52 the shield may be readily swungbackwards, or counter-clockwise as viewed in Figure l, for cleaningpurposes should it'become clogged with cement dust or other materials,and upon release it will drop to its original position where it will bemaintained by the materials as they pass through the hopper. The

non-rigid mounting of the shield also produces a tendency toward theautomatic clearing of the vent through vibration of the parts when themachine is in use.

Any suitable means for reciprocating the hopper to and from itsoperative position may be prov port andhaving a bracket member withinsaid hopper extending across said port from the pe-.

r the perimeter of said member to its axis, the invided, those hereshown being similar to the means disclosed in the said Ball Patents Nos.2,265,751 and 2,265,752 and including a manually operable shaft carryinga pair of operating arms Bl extending downwardly, one to either side ofthe hopper 13. The lower ends of these said arms are connected throughresilient'or compressible connections 63 similar to those described ining from the spirit of the invention and there- .fore it is not wishedto be limited to the above disclosure except as may be required by theclaims.

What is claimed is:

1. In a concrete mixer, means for mounting a non-rotatable charginghopper upon a rotatable concrete mixing drum for reciprocatory movementstoward and from a material-transfer openingin one end of said drum, saidhopper having a discharge port co-operatively registerable with saiddrum opening for the transfer of materials from the hopper into thedrum: said hopper mounting means comprising a collar structure securedto the hopper 'around said rimeter to the axis of the latter; meanscarried by said collar structure whereby the collar and hopper may bemoved toward and from the drum opening; a shaft for supporting saidhopper having one end portion mounted in said bracket in substantiallythe plane of said hopper port and projecting therefrom axially throughsaid drum opening; and a hearing within and rotatable with the drum,slidably supporting the projecting portion of said shaft for movementsaxially of the drum.

2. An element for mounting a charging hopper .upon a rotatable concretemixing drum with the discharge port of the hopper in co-operativereciprocatable relation to a material-transfer opening in an end of thedrum, said element comprising an annular member securable to the hoppersurrounding its discharge port and having a substantially radial bracketan arm extending from ner end of said bracket arm being formed toreceive a portion of a hopper-supporting shaft mounted bythe mixing drumaxially of its transfer opening, said annular member also havingoppositely disposed trunnions for connection to a hopper reciprocatingmeans.

3. The combination with a charging hopper for Y concrete mixer drums,having a wall provided with, a discharge port through which theconcrate-making materials pass into the drum, of a shield membernon-rigidly mounted in the hopper adjacent said wall and extending intosaidport sufiiciently to provide a channel for the escape of airtherethrough during the occupancy of the remainder of the port bymaterials passing thrcl h said hopper, the non-rigid mounting of saidshield member providing for its vibratory agitation during operation ofthe apparatus to tend to automatically clear the channel of materialswhich may enter and deposit therein.

4. In a charging hopper for concrete mixer drums, having a wall providedwith a discharge port through which the materials pass to the drum, ahopper supporting member having an apertured portion disposed within thearea'of said port; and means for venting the drum during chargingcomprising a shield member pivotally mounted adjacent said hopper wall,the upper portion thereof being in open communication with theatmosphere and the lower portion thereof embracing the aperture in saidsupporting member. l

LOUIS G. HILKEMEIER.

CERTIFICATE OF CORRECTION. Patent ,No. 2,562 ,L 55. November], 19th.

LOUIS c. HILKEIIE-iER;

It is hereby certified thaterror appears in the printed specification ofthe above numbered. patent requiring correction as follows: Page 5, sec-0nd column, line 56-, claim 2; after the word bracket strike out "an andthat the said Letters Patent shouldbe readwith this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 15th day of February, A. 1). 19t5.

Leslie Frazer (Seal) Acting Commissioner of Patents.

